Mercury cathode electrolytic cell



Aug. 18, 1953 H. sl-{Aw ET Al. 2,649,411v

MERCURY CATHODE ELECTROLYTIC CELL Filed Jan. 24, 1950 INVENTORS: Jljazrzly Shaw, Alhe' Thompzonb/ Thomas12LIjo1er, BY

af/www l w1/MMO ATTORNEYS.

Patented Aug. 18, 19.5.3

UNITED STATES Y PATENT OFFICE MERCURY CATHODE ELECTROLYTIC CELL Harry Shaw, Albert Thompson, and Thomas I. J. Toler, Runcorn, England, assignors to Imperial Chemical Industries Limited, a corporation of Great Britain Application January 24, 1950, Serial No. 140,228 In Great Britain February 7, 1949 maintain the size of the interelectrode gap and the efficiency of the cell. Various means have been described for adjusting the anode height. in flowing cathode mercury cells, either separately or in association with means for sealing the upper to the lower part of the cell.

In copending application Serial No. 20,564, of G. T. Meiklejohn, now U. S. Patent No. 2,596,583, there is described and claimed an electrolytic cell incorporating an automatic and continuously acljusting assembly in which the graphite anode masses are supported within the cell by means of a series of relatively small bodies resting on the cell bottom and so shaped as to make only linear, i. e., edge surface, contact with the anodes whi-ch anodes may be modified to secure the required linear contact and convenient positioning of the supporting bodies. 4Conveniently the supporting bodies employed in the vsaid adjusting means are in the form of cones, the vertices of which penetrate suitably-shaped cavities in the anode masses. ceeds, and disintegration takes place at the lower surface of the anodes, the anodes descend gradui.

ally and continuously on the supporting bodies', so that the interelectrode gap remains approximately constant in size and the ecien-cy of the cell is thus maintained.

The present invention which is an improvement in and modification of the cell and adjustving means described in copending application No.

20,564 of G. T. Meiklejohn, now U. S. Patent No. 2,596,583, and, in particular, relates to a new and convenient means of maintaining the gastightness in such cells, while permitting the free downward movement of the anodes under gravity.

We have found that in cells employing the automatic adjusting means above described, the sealing of the cell may be achieved in a surprisingly effective manner by providing a thin sheet of flexible material, resistant or made resistant to the cell gases, wide enough to span the width of the cell and of a convenient length to form the As the electrolytic process pros claims. (c1. 204-219) cov-er thereof, the said thin sheet having holes to t Ythe supporting rods of the anodes and being provided with sealing means adapted to prevent the escape of gas through the hole and past the anode supporting rod. In an advantageous form of the invention the supporting rods may be machinecl so that the diameter of the upper portion is less than the lower, thus forming a horizontal shoulder on the supporting rod, the joint between the supporting rods and the ilexib1e sheet being thenmade by means of a joint-ring of resilient material between the horizontal shoulder thereon and the inside surface of the flexible cover andA another similar joint-ring between the .outside surface of the flexible sheet and a metal coverdome over the upper end of the anode supporting'.

rod. Electrical contact with the anode supporting rod may be made by means of a vertical copper conductor tted into the supporting rod and passing through the metal -cover-dome, the whole assembly being maintained tight by means of a nut on the copper conductor, which nut holds.

down the cover-dome on to the part of thesupporting rod external to the cell.

An advantageous form of the invention will now be described with reference to the attached formed of polymerized methyl methacrylate and.

drawing. In the drawing Figure 1 shows a vertical section through a cell Aconstructed accordingl to the invention and Figure 2 is a vertical section showing in detail a suitable means of sealing the anode supporting rods to the flexible cell cover.L Figure 3 shows a vertical section through a pre-- ierred means of sealing the supporting rod to the cell cover. In the gures similar numbers refer to similar parts. The flexible cover I is is tightly secured to the ilange of the lower part of the cell by means of a metal strip 2, which strip is held in position by bolts 3, 3. The anode 4 of the cell has an undersurface substantially parallel to cell base plate 2| and is supported substantially by a series of small conical pegs 5, 5 of insulating material which have stems projecting into cavities 6, 6 in the underface of the anode block. This method of supporting the anode is more fully described in copending application No. 20,564 of G. T. Meiklejohn, now U. S. Patent No. 2,596,583. The upper ends of the anode supporting rods 1, 'l are so machined that they are provided with a horizontal shoulder 8, between which shoulder and the exible cover I there is located a joint-ring 9 made of soft rub- -ber neoprene or other resilient material. Above the flexible cell cover there is located a similar joint-ring Il) which is held tightly on to the nexible cover by the base-flange of a metal coverdome I I, which cover-dome is held in position by a nut I2, screwed to a threaded vertical metal spindle I3 which. is. fixed into. the upper part of the anoder supporting` rod and. passes throughA a hole inthe top of the -cover-dome. It is found advantageous to corrugate the flexible cover asv shown at I4 in both Figures 1 and 2; this has the effect of promoting greater Iocaliexiljility.:

in the regions Where the anode supporting rods are sealed to the cover.

InuFigure'S, inzwh'chzsimrllar numbers-refer to-v similaifzpartsatoe thosey shown infFiguresiI auch 2, there is shown. anotherY preferred meansof seal;- ing'. thefanodesupportingi rodto-.the flexible-cell cover; In; this embodiment the. resilient jointe ring above-thefflexi'ble; coverf isfhel'dflrmly in position'. by. means.: of".y a.: mild? steel ring: which Lis. Screwedfozr tol a threaded .portion Ifi of the-anode supporting rod.. Thelel'ectricalconnection to the` anode. may conveniently be: made: byv means Lof' The corrugat'ons.- run lengthwise either across the entirew-idth of the.

The use of the nut lfor' theipurp'ose.of"A

anut` ITI xe'dl'tof a metalfstirrupi whichfi'si held by nuts: t9, IfQatthe endsof a rod Z0 whichpassesf through. the upper partofthe: anode;supporting rod:

Witlfr'regard. to the celll cover," which may beef any suitable flexibler and resistant' material; it'V isi to,` benoted that" this may be constructed from several! nexi-ble' sheets, suitably jointedftogethertomaintain the gas-tightness of the cell?, polymerised methyl methacrylatebeing particularly'. sui-table'k for building uptheI celll coverl this way',` since the individual sheets maybe cemented` together at: their' edges b'y mea-nsof'fcement vcomprising the: monomer containing' the polymer solution.

Since many changesV may be'r mad'e'- in the de tails and illustrations set forth above Witt-'loutAV departing. from' thespirit-and scope ofthe inven- 4 ltion, it is to fbe understood that the invention is not limited to such details except as indicated in the appended claims.

We claim:

1.. A ilovving;.mercuryv cathode electrolytic cell havingfcontinuous andi-automatici adustment of the height of the anode, comprising in combination a substantially horizontal cell base plate for supporting a owing mercury cathode, side walls, an; anodehaving'anl undersurface substantially parallelto said. base plate, an array of small supportingjhodiesresting on the cell base plate supportingathez-majorpart of the Weight of the anode above saidcelfl basezplate, said bodies making edge surface contact only with the said anode, an integralverticallynexible cover on the cell, said ycover' being" substantially uniformly flexible throughout and the edge of said vertically flexible cover being rigidly xed to the said side Walls ofthe cell,.V anode sliplzvorting.rodsV extendingffrom the; upper surface of, the, anode .throughholes saidilexible cover'and means. xedly sealing.. said. rodete. .sadfcaver whereby the; covenis causedfto move with said anode as anode wear takes place.

2., An. electrolytic.. cell. as4 claimedin claim. 1 wherein.. the.. flexible cell coverY made, o1 polymerized methyl metlaorylate..

3,1 An elctrolytic cell as claimed in claim 1. whereinthe iexi'bl'e, cell. cover ismade offa. thin.

sheet-metal.. said metallbeing .protected from the. action ofelectrol'yti'c gases by means. of a. coating of bituminous paintr 4; electrolytc. cell.' as..claimed in claim. l.

p wherein' the exibl'ecellfcover is made of' poly- 5: An electrolyti'c cell asclaimedin. claim I,v

having, lengthwise corrugations in thev cover at least` the: region ofith'e cover through. which saidanode. supportingv rods extend;

I-IARRYSI-IAW ALBERT' 'I'IiIOMPS'ON'.V THOMAS II J.' TOLER.

OTHER f REFERENCES Horizontal`Mercury- Chlorine Cell. Fiat. Re portiN'o; 816;' May' I5, I9'4'6.,.pages 1.4,. 18, 2l. and.22l. Ofllce' ofTechnicalServices, .UZ S; Dept.. of. Commerce; Washington.. DI C. 

1. A FLOWING MERCURY CATHODE ELECTROLYTIC CELL HAVING CONTINUOUS AND AUTOMATIC ADJUSTMENT OF THE HEIGHT OF THE ANODE, COMPRISING IN COMBINATION A SUBSTANTIALLY HORIZONTAL CELL BASE PLATE FOR SUPPORTING A FLOWING MERCURY CATHODE, SAIDE WALLS, AN ANODE HAVING AN UNDERSURFACE SUBSTANTIALLY PARALLEL TO SAID BASE PLATE, AN ARRAY OF SMALL SUPPORTING BODIES RESTING ON THE CELL BASE PLATE SUPPORTING THE MAJOR PART OF THE WEIGHT OF THE ANODE ABOVE SAID CELL BASE PLATE, SAID BODIES MAKING EDGE SURFACE CONTACT ONLY WITH THE SAID ANODE, AN INTEGRAL VERTICALLY FLEXIBLE COVER ON THE CELL, SAID COVER BEING SUBSTANTIALLY UNIFORMLY FLEXIBLE THROUGHOUT AND THE EDGE OF SAID VERTICALLY FLEXIBLE COVER BEING RIGIDLY FIXED TO THE SAID SIDE WALLS OF THE CELL, ANODE SUPPORTING RODS EXTENDING FROM THE UPPER SURFACE OF THE ANODE THORUGH HOLES IN SAID FLEXIBLE COVER AND MEANS FIXEDLY SEALING SAID RODS TO SAID COVER WHEREBY THE COVER IS CAUSED TO MOVE WITH SAID ANODE AS ANODE WEAR TAKES PLACE. 